1. Field of the Invention
The present invention relates to burglar alarms, and more particularly pertains to a spring powered mechanical portable burglar alarm which does not require the use of electrical power sources or compressed gas canisters.
2. Description of the Prior Art
Various types of burglar alarms are known in the prior art. A typical example of such a burglar alarm is to be found in U.S. Pat. No. 452,597, which issued to C. Davis on May 19, 1891. This patent disclose a portable mechanical burglar alarm for monitoring a door or window. A trigger blade of the alarm is adapted for insertion in the crevice between a door or window and the associated frame. The device includes an oscillating clapper arm powered by a coil spring and gear mechanism. U.S. Pat. No. 568,532, which issued to I. Hauser on Sept. 29, 1896, discloses a combined burglar alarm and call bell having a bell mechanism actuated by a coil spring. U.S. Pat. No. 589,540, which issued to J. Towler on Sept. 7, 1897, discloses a burglar alarm including a mechanical bell clapper actuated by a coil spring and gear mechanism. A release trigger is formed by an elongated adjustable plunger. U.S. Pat. No. 3,921,56 which issued to H. Murray on Nov. 25, 1975, discloses a portable burglar alarm having a housing containing a bell and a spring driven motor. The alarm has an elongated supporting mechanism connected to the housing and operatively coupled to the spring driven motor. The alarm is adapted for leaning the housing against a movable surface, with the elongated supporting mechanism resting on a fixed surface. Relative movement of the movable surface causes the alarm to topple and engage the spring driven motor to mechanically ring a pair of spaced bells. U.S. Pat. No. 4,067,289, which issued to C. Joyner, Jr. on Jan. 10, 1978, discloses a portable mechanical alarm for doors and windows which utilizes a mechanical clapper arm to strike a bell. A trigger arm is operative to activate the bell ringing mechanism.
While the above mentioned devices are directed to portable mechanical burglar alarms, none of these devices disclose the use of a spring powered bell ringing mechanism having a trigger mechanism and a trigger retaining mechanism for preventing unauthorized resetting of the trigger mechanism. Inasmuch as the art is relatively crowded with respect to these various types of burglar alarms, it can be appreciated that there is a continuing need for and interest in improvements to such burglar alarms, and in this respect, the present invention addresses this need and interest.